Vehicle cooling fan

Abstract

A cooling fan for a vehicle. Many engine compartments of motor vehicles are small in size, and contain numerous components. Electric cooling fans are used to draw air through a radiator. Given the cramped conditions within the engine compartment, the exhaust of the fan cannot be directed into open air, but must impinge on one or more of the components within the compartment. This situation reduces velocity in the exhaust, and also reduces efficiency of the fan. The invention provides a collection of generally co-axial stators which divert the exhaust around the components, while retaining much of the velocity of the exhaust.

1 . An apparatus comprising: 
 a) a fan which produces an exit flow toward an obstacle in the exit flow; and    b) vanes upstream of said obstacle which divert a portion of the exit flow into a radial direction.    
   
   
       2 . The apparatus according to  claim 1 , wherein said fan, obstacle, and vanes are located in the engine compartment of a vehicle.  
   
   
       3 . The apparatus according to  claim 2 , wherein said fan draws cooling air through a heat exchanger which cools engine coolant and/or a condenser that cools refrigerant for the vehicle air conditioning system.  
   
   
       4 . The apparatus according to  claim 1 , wherein said fan is generally an axial flow type.  
   
   
       5 . The apparatus according to  claim 1 , wherein said vanes mitigate reduction in fan efficiency caused by the obstacle.  
   
   
       6 . The apparatus according to  claim 4 , wherein at least three vanes are present, and radial spacing between one pair of neighboring vanes is different from radial spacing between a second pair of neighboring vanes.  
   
   
       7 . The apparatus according to  claim 1 , wherein a plurality of said vanes have different chord lengths.  
   
   
       8 . The apparatus according to  claim 1 , wherein said fan is of the axial flow type and 
 i) vanes which are relatively near the axis are relatively far from said fan, and    ii) vanes which are relatively far from the axis are relatively near to said fan.    
   
   
       9 . The apparatus according to  claim 1 , wherein said vanes are generally ring-shaped, and larger diameter vanes are closer to said fan than smaller diameter vanes.  
   
   
       10 . The apparatus according to  claim 1 , wherein at least one of said vanes has an inlet angle IA- 1  and another of said vanes has an inlet angle IA- 2 , different from IA- 1 .  
   
   
       11 . The apparatus according to  claim 1 , wherein at least one of said vanes has an inlet angle IA- 1  and another of said vanes has an inlet angle IA- 2 , is equal to IA- 1 .  
   
   
       12 . The apparatus according to  claim 1 , wherein at least one vane has an exit angle EA- 1  and another of said vanes has an exit angle EA- 2 , different from EA- 1 .  
   
   
       13 . The apparatus according to  claim 10 , wherein all inlet angles of said vanes at similar angular positions are similar.  
   
   
       14 . The apparatus according to  claim 12 , wherein all exit angles of vanes having similar angular positions are similar.  
   
   
       15 . The apparatus according to  claim 1 , wherein the fan is generally an axial-flow type and at least some vanes span an arc of less than  360  degrees.  
   
   
       16 . The apparatus according to  claim 14 , wherein vanes at different radii span different arcs.  
   
   
       17 . The apparatus according to  claim 1 , wherein radial struts support the vanes, and the radial struts do not significantly re-direct tangential exhaust from the fan into axial flow.  
   
   
       18 . The apparatus according to  claim 1 , wherein radial struts support the vanes, and re-direction of tangential exhaust from the fan into axial flow by the radial struts is minimal.  
   
   
       19 . An apparatus, comprising: 
 a) a vehicle;    b) within the vehicle, a cooling fan which generates a generally cylindrical airflow toward an obstruction downstream of said fan; and    c) one or more stators between said fan and said obstruction, which turn generally axially flowing air into generally radially flowing air.    
   
   
       20 . The apparatus according to  claim 19 , wherein said fan, obstruction, and stators are located in the engine compartment of a vehicle.  
   
   
       21 . The apparatus according to  claim 19 , wherein said fan draws cooling air through a heat exchanger which cools engine coolant and/or a condenser that cools refrigerant for the vehicle air conditioning system.  
   
   
       22 . The apparatus according to  claim 19 , wherein said fan is an axial flow fan.  
   
   
       23 . The apparatus according to  claim 19 , wherein the said vanes mitigate reduction in fan efficiency caused by the obstacle.  
   
   
       24 . The apparatus according to  claim 23 , wherein at least three stators are present, and radial spacing between one pair of neighboring vanes is different from radial spacing between a second pair of neighboring vanes.  
   
   
       25 . The apparatus according to  claim 19 , wherein different ones of said stators have different chord lengths.  
   
   
       26 . The apparatus according to  claim 19 , wherein said fan has a central axis defined therein and 
 i) stators which are relatively near the axis are relatively far from the fan, and    ii) stators which are relatively far from the axis are relatively near to the fan,    
   
   
       27 . The apparatus according to  claim 19 , wherein said stators are generally ring-shaped, and larger diameter stators are closer to the fan than smaller diameter vanes.  
   
   
       28 . The apparatus according to  claim 19 , wherein one of said stators has an inlet angle IA- 1  and another stator has an inlet angle IA- 2 , different from IA- 1 .  
   
   
       29 . The apparatus according to  claim 19 , wherein one stator has an exit angle EA- 1  and another stator has an exit angle EA- 2 , different from EA- 1 .  
   
   
       30 . The apparatus according to  claim 28 , wherein all inlet angles of stators at similar angular positions are similar.  
   
   
       31 . The apparatus according to  claim 29 , wherein all exit angles of stators having similar angular positions are similar.  
   
   
       32 . The apparatus according to  claim 19 , wherein said fan is generally an axial-flow type and at least some stators span an arc of less than 360 degrees.  
   
   
       33 . The apparatus according to  claim 32 , wherein stators at different radii span different arcs.  
   
   
       34 . The apparatus according to  claim 19 , wherein radial struts support the stators, and the radial struts do not significantly re-direct tangential exhaust from the fan into axial flow.  
   
   
       35 . The apparatus according to  claim 19 , wherein radial struts support the stators, and re-direction of tangential exhaust from said fan into axial flow by the radial struts is minimal.  
   
   
       36 . An apparatus, comprising: 
 a) a generally axial-flow fan which produces exhaust having polar coordinates (r, theta, z) defineable therein;    b) vanes present in the exhaust, which increase radial component of the exhaust; and    wherein vanes at different coordinates (r, theta, z) have different geometries.    
   
   
       37 . The apparatus according to  claim 36  and further comprising a vehicle having an engine compartment, wherein the fan and the vanes are located in the engine compartment.  
   
   
       38 . The apparatus according to  claim 36 , wherein an obstacle is present in the exhaust, and the vanes divert exhaust around the obstacle.  
   
   
       39 . The apparatus according to  claim 36 , wherein inlet angles of vanes at a common angle theta are similar.  
   
   
       40 . The apparatus according to  claim 36 , wherein exit angles of vanes at a common angle theta are similar.  
   
   
       41 . The apparatus according to  claim 36 , wherein, at a given z-coordinate, vane geometry is non-uniform for all theta.  
   
   
       42 . The apparatus according to  claim 36 , wherein vanes at different r-coordinates span different angles theta.  
   
   
       43 . The apparatus according to  claim 19 , wherein adjacent vane pairs define a channel therebetween, and different channels have different widths.  
   
   
       44 . The apparatus according to  claim 36 , wherein a first vane of a first radius spans an arc A 1 , and a second vane of a second radius spans an arc A 2 , different from A 1 .  
   
   
       45 . An apparatus, comprising: 
 a) a generally axial-flow fan which produces an exhaust,    b) means present in the exhaust for reducing a change in angle-of-attack of blades in the fan, which change is caused by an obstacle in the exhaust.    
   
   
       46 . The apparatus according to  claim 45 , and further comprising a motor vehicle which carries said fan and the means in an engine compartment.  
   
   
       47 . An apparatus, comprising: 
 a) a cooling system;    b) a generally axial-flow cooling fan for use in a vehicle having an obstruction in said vehicle downstream of the cooling fan which, if exhaust of the fan is allowed to reach the obstruction unimpeded, diverts the exhaust into radial directions with an average speed V 1 , and    c) a set of stators between the fan and the obstruction, which divert the exhaust into radial directions with an average speed V 2 , higher than V 1 .    
   
   
       48 . A method for improving cooling of an engine in a vehicle, said method comprising the steps of: 
 situating a set of stators or vanes in an airflow path between a fan and an obstruction to divert exhaust in a generally radial direction at a speed that exceeds the speed at which airflow is diverted by said obstruction.